I think when you typed what you did, you were pretty anger then, I have really had to pull your words around to get the drift. So here goes. Are you saying that your daughter was married over 10 days ago, and that she was a bridesmaid once at one of the cousins marriages previously. But these cousins & their mother your daughters Aunt have come to the wedding without so much as a card let alone a gift for your own daughters wedding? No I am not being sarcastic, but I do feel your so mad about this all (and rightfully so), that you thumped the keys on the keypad down so hard and never paid attention how your words would read).
There is no excuse for what these relatives have done to your daughter and her new husband and to you the parents of the bride. No wonder your so fuming, I would be spitting rockets out of my mouth by now too.
Even if your story is the other way I see your engaged words were typed as saying, that your daughter was the bridesmaid 10 days ago, then yes its still bloody rude of them not to have at least given the bridesmaid a customary little gift, or at least to have informed the bridesmaids or their parents that they had little money to do so, seeing as weddings cost a fortune. But if its your daughter that was the bride and her Aunt and the cousins did not at least say they could only afford a small gift, they should have said so before the wedding. We all understand how it can be at times when we are hard up, it would have just been polite to have said something and not nothing at all.
For a start I would have a go at this other family for sure, and say that whilst you understand that money at times can be tight, they should have had the common decency to have forewarned you, so that you could have explained to your daughter saving them the embarrassment. What a mean bunch. I bet they all came dressed up with new gear on though, drunk all the drink, ate all the food, and besides they could have clubbed together and gotten the couple something at least. I can well see where this could lead to a family rift too, that could possible cut one side off from the other side. I do see your hurt and frustration, and as for the Bride herself she must indeed feel very very hurt. It's not just about a gift, certain celebrations like marriages and christening is all about good wishes, whereas with birthdays and Christmas people sometimes have to forgo a present simply because of the cost. But special celebrations are about wishing a baby or a new husband and wife life long good wishes.
Honest to God I don't know how they had the nerve to attend the wedding in the first place. I would air your feelings out with them, for it is eating you up inside, it would me and thousands of others too, get it off your chest, say it in a calm and polite tone, and then when the excuses start rolling in, say '' then why the hell could you have not come to me and told me you were in financial difficulties''. Make them feel guilty too and add '' how do you feel what you did makes your niece feel like''.
Get all this off your chest woman, or it might not just be spitting rockets that you will have to contend with, you may well blow your whole self up in an explosion your feeling so hurt and angry.
You can choose your friends in life, unfortunately you cannot choose your family.